no wonder people are buying older pick ups , I know I still drive my 2005 2dr blazer 4x4 and my 1991 GMC 1500 . parts are cheap for them hey and no payments .
I know this is a dumb question but why did plugging the pvc affect the fuel trims .as usual I enjoyed your video thanks for sharing your time and knowledge.
The Positive Crankcase Ventilation system draws fumes off the crankcase. If there's gasoline in the oil it will run rich causing the negative fuel trims. If the fuel trims return to normal with the PCV disabled and plugged off that strongly suggests there's gas in the oil. HTH
I had/have this issue. Just got alcohol fuel level reset as it was at 54%. Long term has come down to around -20% now. Was at -25%. Another issue has arisenn now though. Rough idle and weird acceleration after changing MAF sensor. Gor it from Napa. So think its rhe right one. Still acts weird if i put old one back in too. I've checked for vacuum leaks. Also has new plugs, leads, coils, air filter, fuel rail pressure sensor and fuel pump. Between me and the mechanic, we've made it worse 😂. Any suggestions? It's a 2008 Chevrolet Express AWD 5.3 flexfuel
After resetting the alcohol percentage you need to clear the fuel trims. I gather you are not using e85. If the fuel trims at idle are more than 10% negative on one or both banks try disconnecting the forward O2 sensors to force it to open loop. If the forward O2s are reading false rich it could try to lean it out
P0171, 174 are lean codes. Could have low fuel pressure, plugged fuel filter or induction leak. Could also have a dirty MAF sensor. I'd start by checking fuel pressure and or replacing the fuel filter. You did say it's an 02 right?
@@emerievsalgado2289 check the fuel pressure, try disconnecting the forward O2 sensors. Could still have a bad MAF sensor. What brand did you put in? Induction leak. Lots of possibilities...
💯
Thanks for your time
Thank you
no wonder people are buying older pick ups , I know I still drive my 2005 2dr blazer 4x4 and my 1991 GMC 1500 . parts are cheap for them hey and no payments .
I know this is a dumb question but why did plugging the pvc affect the fuel trims .as usual I enjoyed your video thanks for sharing your time and knowledge.
The Positive Crankcase Ventilation system draws fumes off the crankcase. If there's gasoline in the oil it will run rich causing the negative fuel trims. If the fuel trims return to normal with the PCV disabled and plugged off that strongly suggests there's gas in the oil. HTH
@@PhillipBailey yes sir it does thank you
That means HPFP is leaking in crank case , leaking injector will keep the system rich from that bank of the leaking injector
That is correct
I had/have this issue. Just got alcohol fuel level reset as it was at 54%. Long term has come down to around -20% now. Was at -25%. Another issue has arisenn now though. Rough idle and weird acceleration after changing MAF sensor. Gor it from Napa. So think its rhe right one. Still acts weird if i put old one back in too. I've checked for vacuum leaks.
Also has new plugs, leads, coils, air filter, fuel rail pressure sensor and fuel pump.
Between me and the mechanic, we've made it worse 😂. Any suggestions?
It's a 2008 Chevrolet Express AWD 5.3 flexfuel
After resetting the alcohol percentage you need to clear the fuel trims. I gather you are not using e85. If the fuel trims at idle are more than 10% negative on one or both banks try disconnecting the forward O2 sensors to force it to open loop. If the forward O2s are reading false rich it could try to lean it out
@@PhillipBailey awesome. Thanks alot. Really appreciate it 👍
And no, no e85 here. I use regular gasoline. Which I believe is 87
Chevy tahoe 2002 lt 5.3 P0171 & p0174 can you help me, please
P0171, 174 are lean codes. Could have low fuel pressure, plugged fuel filter or induction leak. Could also have a dirty MAF sensor. I'd start by checking fuel pressure and or replacing the fuel filter. You did say it's an 02 right?
I already changed mass sensor,fuel filter,fuel pump,few coil,spark plug, wires
@@emerievsalgado2289 check the fuel pressure, try disconnecting the forward O2 sensors. Could still have a bad MAF sensor. What brand did you put in? Induction leak. Lots of possibilities...